mm/hugetlb.c: remove unnecessary initialization of local `err'

Link: https://lkml.kernel.org/r/20220905020918.3552-1-zeming@nfschina.com
Signed-off-by: Li zeming <zeming@nfschina.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/hugetlb.c

@@ -3718,7 +3718,7 @@ static ssize_t demote_store(struct kobject *kobj,
 	unsigned long nr_available;
 	nodemask_t nodes_allowed, *n_mask;
 	struct hstate *h;
-	int err = 0;
+	int err;
 	int nid;
 
 	err = kstrtoul(buf, 10, &nr_demote);